RU2704223C2 - Panel for lining and/or sound insulation of vehicle wall and method for manufacturing thereof - Google Patents

Abstract

FIELD: transportation.

SUBSTANCE: present invention relates to a panel for lining and/or sound insulation of a vehicle. Disclosed is panel (10) for lining and/or soundproofing of roof or side walls (walls) of vehicle, comprising: central layer (14) made by impregnation (46) of polyester (20) with epoxy powder (21) followed by curing epoxy powder (21), and two reinforcing layers (13, 15) located on both sides of central layer (14), in which impregnation (46) of polyester (20) with epoxy powder (21) is carried out deep inside polyether (20) by exposing epoxy powder (21) alternating electric field, wherein two reinforcing layers (13, 15) are made using a flexible or semi-rigid material. Invention covers also method of making panel.

EFFECT: technical result consists in improvement of performance related to reduction of weight of panel with possibility of thermoforming, as well as improved absorption of sound waves.

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Description

Field of Invention

The present invention relates to a panel for sheathing and / or soundproofing a vehicle, for example, a motor vehicle. Said panel is particularly suitable as a panel for cladding and / or soundproofing the interior of a motor vehicle, for example, such as panels located under a roof or on side walls.

State of the art

There are many restrictions on the dashboards of automobile vehicles. These panels must be lightweight to optimize the vehicle mass, they must be thermoformed to follow the contours of the vehicle, they must effectively absorb sound waves and limit noise inside the vehicle, they must comply with fire safety requirements and must be dense to avoid deformation over time time. There are several ways to make such a material.

Patent application FR 2 503 721 describes a method for manufacturing a panel that complies with these restrictions. The specified panel is made of a Central layer and two reinforcing layers located on both sides of the Central layer. The central layer meets the requirements of lightness, flexibility and sound absorption, while the two reinforcing layers meet the requirements of mechanical strength. To achieve this, the central layer is made of foam impregnated with a liquid resin, which is then crosslinked. The resin used is MDI (4,4'-diphenylmethanediisocyanate). The upper surface is covered with a protective layer made to come into contact with the vehicle element, and the lower surface is covered with a decorative layer to improve the aesthetics of the panel perceived by the user of the vehicle. The resin contained in the foam hardens when all layers are bonded during thermoforming, resulting in the panel acquiring the desired shape.

However, the mechanical strength of the crosslinked foam is insufficient, which requires the use of particularly hard reinforcing layers, for example, fiberglass. Fiberglass reinforcing layers are a problem in terms of panel recycling. Often, part of the panel is cut out to make an opening for the glass roof in the vehicle. In such cases, the part of the panel removed for the glass roof is cut and discarded. The presence of tar and glass in these wastes limits recycling.

This panel manufacturing method imposes additional restrictions, since the liquid resin is fed into the foam by means of sealing rollers in order to impregnate the foam, which is subsequently placed in contact with the catalyst. The reaction of the catalyst with the resin causes the release of volatile compounds (VOCs) into the air, which can cause a foul odor, which is unpleasant for workers involved in the manufacture of panels. Moreover, the panel must be molded before the resin forms cross-links, which requires constant movement of the production line. For example, if the assembly line stops, the resin-impregnated foam begins to solidify before it enters the thermoforming mold and the incomplete parts must be discarded.

The method of impregnating the foam with the resin must also be carefully adjusted for each batch of parts, since the amount of resin in the foam is extremely important. If the foam contains too much resin, the resin will flow through the decorative layer and will be visible at the corners, disfiguring the decorative layer. If the foam contains too little resin, the panel will be too soft, and will not have sufficient mechanical strength. Reducing the amount of resin for each batch of parts to perfect is a complex iterative process that requires a lot of experience.

Thus, there is a need for a new panel for a car interior that meets the above requirements, but is characterized by an improved manufacturing method.

Description of the invention

The present invention relates to a new material that meets all the above requirements, but the foam is impregnated in a dry manner without impregnation with liquid.

A first aspect of the present invention relates to a panel for decorating and / or soundproofing a wall of a vehicle, said panel comprising:

a center layer formed by impregnating a flexible and porous material with a thermoformed resin, followed by curing of the thermoformed resin, and

- two reinforcing layers located on both sides of the Central layer,

- while impregnation of the flexible and porous material with a thermoformed resin is carried out deep inside the flexible and porous material by exposing the powder from the aforementioned thermoformed resin to an alternating electric field,

- wherein two reinforcing layers are made of flexible or semi-rigid material.

The present invention thus provides a panel for the interior of an automobile vehicle, which is simultaneously lightweight, thermoformable, soundproof, meeting all safety and compactness requirements. The flexible and porous material forming the core layer may advantageously be a foam consisting at least partially of open cells.

Impregnation with resin deep inside the cellular core of the foam and the use of reinforcing layers made of flexible or semi-rigid materials improves resin distribution and cohesion between the reinforcing layers and the center layer. Fiberglass reinforcing layers are no longer necessary, and thus the panel is easier to recycle.

Problems with smell and perfection of the wet manufacturing method are also eliminated in the dry method, and the flexible and porous material is impregnated with a thermoformed resin without using a liquid. The curing of the thermoformed resin can be properly performed after the thermoformed resin has penetrated the material, which removes the time limitations associated with the drying of the thermoformed resin within a flexible and porous material.

According to one embodiment, at least one reinforcing layer is made by impregnating a second porous material with a thermoformed resin powder by exposing it to an alternating electric field. The impregnated dry resins can be cured later; the reinforcing layers can be manufactured in a manner similar to that of the central layer, on an auxiliary production line. Preferably, the second porous material is a non-woven fabric based on synthetic fibers. Alternatively, the second porous material is a web made from natural or other fibers.

According to one manufacturing method, the panel comprises a decorative layer attached by means of a heat-adhesive layer to the surface of the reinforcing layer. Advantageously, the panel also comprises a protective layer attached to one surface of the reinforcing layer by means of a thermal adhesive layer.

According to a second aspect, the present invention relates to a method for manufacturing a panel in accordance with the first aspect of the present invention, the method comprising the following steps:

- the application of thermoformed resin in the form of a powder on a flexible and porous material,

- impregnation of the thermoformed resin deep inside the flexible and porous material by exposure to an alternating electric field passing through the flexible and porous material, and

- attaching a thermoformed resin to a flexible and porous material by softening.

According to a first embodiment of the manufacturing method, the method comprises the following steps:

- installing the lower reinforcing layer on the lower surface of the flexible and porous material before the step of applying the thermoformed resin and

- installation of the upper reinforcing layer on the upper surface of the flexible and porous material before the step of impregnation with thermoformed resin,

- the manufacture of reinforcing layers using a second porous material,

- impregnation with thermoformed resin, made with the possibility of impregnation of the second porous materials of the reinforcing layers.

These embodiments provide the ability to simultaneously impregnate the center layers and reinforcing layers.

According to a second embodiment of the manufacturing method, the method comprises the following steps:

- installing a lower reinforcing layer on the lower surface of the flexible and porous material after the step of impregnation with a thermoformed resin; and

- installation of the upper reinforcing layer on the upper surface of the flexible and porous material after the step of impregnation with thermoformed resin,

- the manufacture of reinforcing layers using a second porous material for each reinforcing layer, the method comprising the following steps:

- the imposition of oh resin in the form of a powder on a second porous material,

- impregnation of the thermoformed resin deep inside the flexible and porous material by exposure to an alternating electric field passing through the second porous material, and

- attaching a thermoformed resin to the second porous material by softening.

The specified embodiment allows you to change the composition of the resin and / or flexible and porous material between the Central layer and the reinforcing layers.

Advantageously, the method includes the following steps:

- the installation of the second porous materials of the reinforcing layers before the step of impregnation with thermoformed resin and

- separation of the two second porous materials after the step of attaching the thermoformed resin by softening,

- the step of impregnation with a thermoformed resin, made with the possibility of impregnation of both second porous materials.

The indicated embodiment provides the possibility of manufacturing two reinforcing layers on the same production line.

According to one embodiment, the step of attaching the thermoformed resin to the flexible and porous material by softening comprises the following steps:

- pressing a flexible and porous material at high temperature, accompanied by thermal bonding, and

- termination of the pressing so that the flexible and porous material re-swells.

This embodiment allows the resin to be dispersed through a flexible and porous material and to bond different layers, taking advantage of the ability of the flexible and porous material to partially restore its original thickness when hot when it is no longer held back.

Said repeated swelling can occur immediately after exiting the device applying pressure to the porous material to produce parts of a relatively thick prefabricated product which are subsequently subject to thermoforming. Re-swelling can also occur during thermoforming, taking advantage of the available heat in the thermoforming device, in which case the parts of the semi-finished product are not so thick, and production equipment is simplified.

According to one embodiment, the resin application step is carried out by scattering it on one surface of a flexible and porous material.

According to one embodiment, the steps of applying and impregnating the resin are performed by topical application. Said embodiment also allows the application of a thermoformed resin and its local impregnation in a flexible and porous material so as to create waste surfaces on which the flexible and porous material is not impregnated with resin or is insufficiently impregnated. These waste surfaces can later be cut out for any particular application, for example, to create a sunroof. These waste surfaces can be recycled more easily than existing waste by decomposing non-impregnated fiberglass-free layers. In addition, this embodiment saves resin.

A brief description of the graphic materials

The method of carrying out the present invention, as well as the advantages provided by it, will be clearly apparent from the following embodiment, provided by way of non-limiting example, in accordance with the accompanying drawings, in which FIG. 1-3 are:

FIG. 1: a schematic representation in accordance with a cross-sectional view of a panel of an automobile interior according to one embodiment of the present invention;

FIG. 2: a schematic representation of a method for manufacturing the panel of FIG. 1, according to a first embodiment of the present invention;

FIG. 3: a schematic representation of a method for manufacturing the panel of FIG. 1, according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 shows a panel 10 for a car interior containing a plurality of layers 11-17. The central layer 14 is surrounded by the upper layers 18 and the lower layers 19. The central layer 14 is directly surrounded by two reinforcing layers 13, 15. The central layer 14 is formed by impregnating 46 thermoformed resin 21 deep inside the flexible and porous material 20, followed by curing of the thermoformed resin 21. For example, the flexible and porous material 20 is a polyester foam formed at least partially from open cells, characterized by a density exceeding 5 kg / m ³ . In the description of this embodiment, the term “foam” will be used to mean flexible and porous material 20.

The impregnation 46 of the thermoformed resin 21 is carried out by exposure to an alternating electric field passing through the foam 20. Each reinforcing layer 13, 15 is attached to the outer layer 11, 17 by means of a thermal adhesive layer 12, 16. For example, the thermal adhesive layer may be a film, a perforated film, a layer of powder or a heat-gluing thread. Preferably, the thermal adhesive layer attached to the decorative layer should be breathable if the foam is to have acoustic properties. The lower reinforcing layer 13 is attached to the decorative layer 11 with a heat-adhesive layer 12, and the upper reinforcing layer 15 is attached to the protective layer 17 with a heat-adhesive layer 16. The reinforcing layers 13, 15 are made using a flexible or semi-rigid material. Preferably, the reinforcing layers 13, 15 are made using a second porous material 23, 63. For example, the second porous material 23, 63 is a non-woven fabric based on synthetic fibers, in particular polyester, characterized by a surface mass density of more than 10 g / m² . In the description of this embodiment, the term “non-woven” will be used to refer to the second porous material 23, 63.

In FIG. 2 shows a first example of an embodiment for manufacturing a panel 10. Foam 20 is wound at the beginning of a production line 60. Said foam 20 is unwound during the manufacturing process to form a panel 10. The first step 40 is to accumulate foam 20 to replace the roll without stopping the production line 60. The lower surface of the foam 20 is then coated with 41 non-woven material 23, which forms a reinforcing layer 13. The next step is to apply 42 thermoformed resin 21 in the form of powder and the upper surface of the foam 20 to form central layer 14. For example, thermoforming resin 21 is an epoxy powder which is characterized by a grain size in the range from 0 to 100 microns. The amount of thermoformed resin 21 to be applied is measured with high accuracy, for example, in the range from 20 to 500 g / m².

According to step 42 for applying the thermoformed resin 21, a non-woven material 63 suitable for forming the upper reinforcing layer 15 is added 43 to the upper surface of the foam 20. The adhesive layer 16 and the protective layer 17 are then added 44 to the non-woven material 63. The adhesive layer 12 and the decorative layer 11 is also added 45 to the nonwoven fabric 23. The product thus obtained is sent to an impregnation chamber 30 having an upper 31 and a lower 32 electrodes to create an alternating electric field passing through foam 20 and non-woven material 23, 63 for moving the thermoformed resin 21 to the center of the foam 20 and non-woven material 23, 63. Preferably, the amplitude of the alternating electric field is in the range from 500 to 5000 volts / mm, mainly in the range from 1000 to 3000 volts / mm at a frequency of approximately 50 Hz. The impregnation chamber 30 thus ensures uniform distribution of the thermoformed resin 21 into the interior of the foam 20 and the nonwoven material 23, 63. During the impregnation 46, the presence of thermo-adhesive layers 12, 16 tightly adhered to the thermoformed resin 21 holds the thermoformed resin 21 inside the foam 20 and nonwoven fabric 23, 63.

When leaving the chamber 30, the obtained product contains all the constituent elements of the completed layers 11-17 with effective impregnation of 46 thermoformed resin 21 of foam 20 and non-woven material 23, 63. The resulting product is pressed 47 at high temperature by calendaring between two sets of cylinders to distribute thermoformed resin 21 to the core of the fibers and to bind the thermoformed resin 21. Then the pressing is stopped 48 at high temperature so that the foam 20 can restore the volume [sic]. At the end of the semi-finished product, 49 are cut according to the desired dimensions and then stored 50. To complete the manufacture of the panel 10, the semi-finished product is thermoformed in a thermoforming shape (not shown) so as to obtain a center layer 14 and reinforcing layers 13, 15. Production line 60 shown in FIG. 2, produces several tens of meters of semi-finished product per minute with a width of several meters. Curing can be carried out after storage and / or transportation of the semi-finished product, which simplifies the manufacturing process of the panels 10. Alternatively, curing can be carried out on the same production line 60, bypassing the steps of cutting 49 and storage 50. Storage 50 can also be carried out by winding the semi-finished product, bypassing such way the cutting step 49.

In FIG. 3 shows a second example of a method of manufacturing a panel 10. In the same manner as for the production line 60 of FIG. 2, foam 20 is wound at the beginning of production line 61. The first step 40 is to accumulate foam 20 to replace the roll without stopping the production line 61. The next step is to apply 42 thermoformed resin 21 in powder form onto the upper surface of the foam 20. Thus obtained the product is sent to a soaking chamber 30 for exposure to an alternating electric field passing through the foam 20, so as to transfer the thermoformed resin 21 to the core of the foam 20.

When leaving the chamber 30, the lower surface of the foam 20 is attached 41 to the lower layers 19, and the upper surface is attached 43 to the upper layers 18. The resulting product contains all the constituent elements of the completed layers 11-17 with effective impregnation of 46 thermoformed resin 21 of the foam 20. The resulting product is pressed 47 at high temperature by calendaring between two sets of cylinders to spread the thermoformed resin 21 to the core of the fibers and to bind the thermoformed resin 21, which covers the inner anstvo cell foam. Then, pressing 48 is stopped at high temperature so that the foam 20 and the nonwoven fabric 23, 63 can restore volume. At the end of the semi-finished product, 49 are cut according to the desired dimensions and then 50 are stored. To complete the manufacture of the panel 10, the semi-finished product is thermoformed in a thermoforming form (not shown).

In contrast to the manufacturing method shown in FIG. 2, the elements forming the reinforcing layers 13, 15 are attached to the heat-gluing layers 12, 16 and to the outer layers 11, 17 on the special production line 62. The specified production line 62 is provided with a nonwoven material 23 wound at the beginning of the production line. The first step 42 ’consists in applying a thermoformed resin 22 in powder form to the upper surface of the nonwoven fabric 23. The amount of thermoformed resin 22 to be applied is measured with high accuracy, for example, in the range from 20 to 500 g / m². After step 42 'of applying the thermoformed resin 22, another non-woven material 63 is added 52 to the upper surface of the non-woven material 23. The thermal adhesive layer 12 and the decorative layer 11 are then added 54 to the lower surface of the non-woven material 23. The thermal adhesive layer 16 and the protective layer 17 also add 53 to the non-woven material 63. The product thus obtained is sent to the impregnation chamber 30 for exposure to an alternating electric field passing through the nonwoven material 23, 63, so as to transfer the thermoformed resin 22 to the hearts well, non-woven material 23, 63. The product thus obtained is pressed 47 at high temperature by calendaring between two sets of cylinders to spread the thermoformed resin 22 to the fiber core and to bind the thermoformed resin 22. Then, the pressing is stopped 48 at high temperature so that the foam and non-woven material 23, 63 can restore volume.

The two nonwoven materials 23, 63 are then separated 56 to obtain constituent elements of both the upper 18 and lower 19 layers. These elements are subsequently used as intermediates for steps 41 and 43 of production line 61. At the end, the final step (not shown) of curing the thermoformed resin 21 of the semi-finished product makes it possible to cure the thermoformed resin 22 of the reinforcing layers 13, 15.

In this example, two reinforcing layers 13, 15 attached to the heat-gluing layers 12, 16 and the outer layers 11, 17 are made on the same production line 62 by combining nonwoven materials 23, 63. Alternatively, two reinforcing layers 13, 15 attached to the heat-gluing layers 12, 16 and the outer layers 11, 17, can be made on independent production lines. Alternatively, the number of layers 11-17 or the arrangement of the outer outer layers 11, 17 of the panel 10 can be changed without changing the invention.

The present invention thus opens up the possibility of producing a panel 10 for a car interior, which is both lightweight and thermoformed, and which absorbs sound waves and meets the requirements of safety and compactness. The flexible and porous material forming the core layer may advantageously be a foam consisting at least partially of open cells.

Claims (36)

1. The panel (10) for covering and / or soundproofing the roof or side walls (walls) of the vehicle, comprising: a central layer (14) made by impregnating (46) the polyester (20) with epoxy powder (21) followed by curing of the epoxy powder (21), and - two reinforcing layers (13, 15) located on both sides of the central layer (14), characterized in that the impregnation (46) of the polyester (20) with epoxy powder (21) is carried out deep inside the polyester (20) by exposing the epoxy powder (21) to an alternating electric field, however, two reinforcing layers (13, 15) are made using flexible or semi-rigid material. 2. The panel according to claim 1, characterized in that the polyester (2) is a foam, consisting at least partially of open cells. 3. The panel according to claim 1 or 2, characterized in that at least one reinforcing layer (13, 15) is made by impregnation with epoxy powder (22) of the second polyester (23, 63), moreover, impregnation (46 ') of the reinforcing layer ( 13, 15) with epoxy powder (22) carried out deep inside the second polyester (23, 63) by exposing it to an alternating electric field. 4. The panel according to claim 3, characterized in that the second polyester (23, 63) is a non-woven material based on synthetic fibers. 5. Panel according to any one of paragraphs. 1-4, characterized in that it further comprises a decorative layer (11) attached to one surface of the reinforcing layer (13, 15) by means of a heat-adhesive layer (12). 6. Panel according to any one of paragraphs. 1-5, characterized in that it further comprises a protective layer (17) attached to one surface of the reinforcing layer (13, 15) by means of a heat-adhesive layer (16). 7. A method of manufacturing a panel (10) according to any one of paragraphs. 1-6, characterized in that it includes the following steps: - overlay (42) of epoxy powder (21) on polyester (20), - impregnation (46) with epoxy powder (21) deep inside the polyester (20) by exposure to an alternating electric field passing through the polyester (20) and - attaching (47) the epoxy powder (21) to the second polyester (20) by softening. 8. The method according to p. 7, characterized in that it includes the following steps: - installation (41) of the lower reinforcing layer (13) on the lower surface of the polyester (20) before the step of applying (42) epoxy powder (21) and - installation (43) of the upper reinforcing layer (15) on the upper surface of the polyester (20) before the step of impregnating (46) with epoxy powder, - the manufacture of reinforcing layers (13, 15) from the second polyester (23, 63), - impregnation (46) with epoxy powder (21), made with the possibility of impregnation of the second polyesters (23, 63) of the reinforcing layers (13, 15). 9. The method according to p. 7, characterized in that it includes the following steps: - installation (41) of the lower reinforcing layer (13) on the lower surface of the polyester (20) after the stage of impregnation (46) with epoxy powder (21) and - installation (43) of the upper reinforcing layer (15) on the upper surface of the polyester (20) after the stage of impregnation (46) with epoxy powder (21), - the manufacture of reinforcing layers (13, 15) from the second polyester (23, 63), however, for each reinforcing layer (13, 15), the method includes the following steps: - overlay (42 ') of epoxy powder (22) on the second polyester (23, 63), - impregnation with epoxy powder (22) deep inside the second polyester (23, 63) by exposure to an alternating electric field passing through the second polyester (23, 63), and - attaching (47 ') the epoxy powder (22) to the second polyester (23, 63) by softening. 10. The method according to p. 9, characterized in that it includes the following steps: - installation (52) of the second polyesters (23, 63) of the reinforcing layers (13, 15) before the step of impregnating (46 ') with epoxy powder (22) and - separation (56) of the two second polyesters (23, 63) after the step of attaching (47 ') the epoxy powder by softening (22), - the stage of impregnation (46 ') with epoxy powder (22), made with the possibility of impregnation of the second two polyesters (23, 63). 11. The method according to any one of paragraphs. 7-10, characterized in that the step of attaching (47, 47 ') the epoxy powder (21, 22) to the polyester (20, 23, 63) by softening comprises the following steps: - pressing at high temperature (47, 47 ') polyester (20, 23, 63) and - termination of pressing (48, 48 ') so that the polyester (20, 23, 63) re-swells. 12. The method according to any one of paragraphs. 7-11, characterized in that the step of applying (42, 42 ') the epoxy powder (21, 22) is performed by dispersing it over the surface of the polyester (20, 23, 63). 13. The method according to any one of paragraphs. 7-12, characterized in that the step of applying (42, 42 ') the epoxy powder (21, 22) and impregnating (46, 46') is performed locally.

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